Novel double- faced thick knitted fabric with flexible structure

ABSTRACT

The invention relates to a thick double-face knitted fabric with a front face ( 1 ) and a rear face ( 2 ), the two faces being connected to one another by means of an intermediate layer ( 3 ), characterized in that it is produced on a circular knitting machine, and in that the intermediate layer ( 3 ) is produced solely from binding monofilaments.  
     A knitted fabric according to the invention has qualities of flexibility and of elasticity and its minimum thickness is 3 mm.  
     The invention also protects the methods and machines for producing the knitted fabric.

[0001] The present invention relates to a novel method for theproduction of a thick double-face knitted fabric having an intermediatespacing structure, a knitting machine of the tucked-stitch circular typefor carrying out the method and the knitted fabric obtained by means ofthe method.

[0002] A thick knitted fabric of this type, described in the Patent EP06 10845, is already known. The spacing threads used are eithermultifilament threads or a combination of multifilament threads and ofmonofilament threads which bind or stitch a row of one face togetherwith the opposite row of the other face. The multifilament threadspreviously undergo a false twist during knitting, and the text mentionsthat they are indispensable for implementation.

[0003] It is also known to produce thick double-face knitted fabricshaving an intermediate spacing structure on flat-bed knitting machines,such as, for example, that described in the U.S. Pat. No. 5,385,036.

[0004] Such knitted fabrics have high crushing resistance, but they havethe disadvantage of lacking flexibility and, for this reason above all,will be reserved for industrial uses which rule out the idea of comfort.

[0005] This knitted fabric is given its properties by virtue of therelative inclination of the binding threads in relation to the twofaces, due to the fact that two binding threads of two different rowsare assembled on one and the same stitch or on two stitches of the samerow of one face, thus giving the binding structure a pyramidal shape.

[0006] The invention is aimed, on the contrary, at obtaining a knittedfabric which is very thick, at least twice as thick as those of theprior art, and at the same time flexible, comfortable, with highelasticity and capable of resuming its initial thickness after prolongedand/or repeated crushings (for example, on vehicle seats).

[0007] These objects are achieved by means of the invention whichconsists of a knitting method for the production of a thick double-faceknitted fabric with a front face and a rear face, the two faces beingconnected to one another by means of an intermediate layer,characterized in that it is carried out according to what is known as a“tucked-stitch” technique on a circular knitting machine, and in thatthe intermediate layer is produced solely with a binding monofilament

[0008] The invention also consists of a thick double-face knitted fabricwith a front face and a rear face, the two faces being connected to oneanother by means of an intermediate layer, characterized in that it isproduced according to what is known as a “tucked-stitch” technique on acircular knitting machine, in that the intermediate layer is producedsolely from binding monofilaments, and in that it has a thickness atleast twice as high as that of standard knitted fabrics.

[0009] Preferably, the monofilament bonds bind to one another a row ofstitches of one face and a row of stitches of the other face, the tworows being racked in relation to one another in the knitting direction,hence two binding threads of two different rows are always bound withdifferent stitches and/or to different rows.

[0010] According to the invention, the intermediate layer is connectedto the front face and to the rear face by means of a binding techniquefrom those generally available (binding by stitch, binding by load,binding by stitch and by load).

[0011] The invention also relates to a special texture of the bindinglayer, given by way of non-limiting example, to its production methodand to a machine for producing it.

[0012] The invention will be understood more clearly from the followingdescription made with reference to the following accompanying figures ofwhich:

[0013]FIG. 1 shows a three-dimensional illustration of a knittedstructure according to the invention, given by way of non-limitingexample,

[0014]FIG. 2 shows a diagrammatic illustration of the steps of theknitting method for producing the knitted fabric of FIG. 1, given by wayof non-limiting example,

[0015]FIG. 3 shows a diagrammatic illustration of the knitting sectionsof a machine according to the invention.

[0016] A knitted fabric according to FIG. 1 is produced on a knittingmachine of the tucked-stitch circular type which produces a front face(1), a rear face (2) and an intermediate layer (3) connecting the twofront (1) and rear (2) faces by means of a monofilament thread (4).According to the knitting method of FIG. 2, illustrating a cycle of 10picks, designated from (I) to (X), bound together with the rows (V₀) to(V₇) and (R₀) to (R₇) of the front and rear faces of FIG. 1:

[0017] picks (I), (II), (III), execution of the rows (V₁) (V₂) (V₃) ofthe front face,

[0018] pick (IV), execution of the row (R₂) of the rear face,

[0019] pick (V), binding between the rows (V₃) and (R₂) of the front andrear faces respectively by means of a monofilament,

[0020] picks (VI), (VII), (VIII), execution of the rows (R₃), (R₄), (R₅)of the rear face,

[0021] pick (IX), execution of the row (V₄) of the front face,

[0022] pick (X), binding of the rows (R₅) and (V₄) by means of amonofilament.

[0023] By virtue of the inclination of the binding monofilaments, theknitted fabric acquires high stability and high elasticity, resistanceto sagging and to lateral slip, and a capacity for resuming its initialthickness after prolonged and/or repeated crushings.

[0024] The texture which has just been described and the method forobtaining it are given by way of example, since other textures arepossible.

[0025] Likewise, the binding technique used in this example is what isknown as a load technique, but what is known as a stitch technique or acombination of these two techniques could also be used.

[0026] In order to distribute the properties of the knitted fabriceffectively in all directions, parallel to the two faces, it isnecessary to prevent two different binding threads from being assembledon the same stitch, as in the rigid knitted fabrics referred to in theprior art. For this purpose, a knitting method according to theinvention is characterized preferably in that two binding threads of twodifferent rows are always bound to different stitches of the same rowand/or to different rows, in such a way that two rows are always rackedin relation to one another in the knitting direction.

[0027] In order to obtain a knitted fabric according to the invention,it is not possible to use standard circular machines which in any caseare more difficult to modify than flat-bed machines. Reorganizationshave been necessary mainly in the region of the set of perpendicularknitting sections (X, Y) (see FIG. 3), on which the setting is at leastdouble the standard setting familiar to a person skilled in the art andpreferably three to four times the standard setting, that is to say:

[0028] standard setting of the prior art: the adjustment (B) in thedirection (Y) is 0.5 to 1.5 times the adjustment (A) in the direction(X).

[0029] setting according to the invention: the value of the adjustments(A) in the direction (X) and/or (B) in the direction (Y) are 3 to 4times the values of the standard adjustments. With the setting accordingto the invention, knitted fabrics which have a minimum thickness of 3 mmare obtained.

1. Knitting method for the production of a thick double-face knittedfabric with a front face (1) and a rear face (2), the two faces beingconnected to one another by means of an intermediate layer (3),characterized in that it is carried out according to what is known as a“tucked-stitch” technique on a circular knitting machine, and in thatthe intermediate layer (3) is produced solely with a bindingmonofilament.
 2. Method according to claim 1, characterized in that thefollowing picks I to X are executed in succession on a tucked-stitchcircular knitting machine: picks (I), (II), (III), execution of the rows(V₁) (V₂) (V₃) of the front face, pick (IV), execution of the row (R₂)of the rear face, pick (V), binding between the rows (V₃) and (R₂) ofthe front and rear faces respectively by means of a monofilament, picks(VI), (VII), (VIII), execution of the rows (R₃), (R₄), (R₅) of the rearface, pick (IX), execution of the row (V₄) of the front face, pick (X),binding of the rows (R₅) and (V₄) by means of a monofilament. 3.Knitting method according to one of claims 1 and 2, characterized inthat two binding threads of two different rows are bound to differentstitches.
 4. Knitting method according to one of claims 1 to 3,characterized in that two different rows are bound to different rows. 5.Knitting method according to one of claims 1 to 4, characterized in thatthe intermediate layer (3) is connected to the front face and to therear face by means of a binding technique selected from all thoseavailable (binding by stitch, binding by load, binding by stitch and byload).
 6. Knitting method according to one of claims 1 to 5,characterized in that a setting of knitting sections on thetucked-stitch circular knitting machine which is at least double thestandard setting is used.
 7. Knitting method according to claim 6,characterized in that the setting is three to four times the standardsetting.
 8. Circular knitting machine for carrying out a methodaccording to one of claims 1 to 7, of the type comprising, inparticular, a set of perpendicular knitting sections (X), (Y),characterized in that the setting of the sections is at least double thestandard setting.
 9. Machine according to claim 8, characterized in thatthe value of the adjustments (A) in the direction (X) and/or (B) in thedirection (X) are 3 to 4 times the values of the standard adjustments.10. Thick double-face knitted fabric with a front face (1) and a rearface (2), the two faces being connected to one another by means of anintermediate layer (3), characterized in that it is obtained by means ofa method according to one of claims 1 to
 7. 11. Knitted fabric accordingto claim 10, characterized in that the monofilament bonds bind to oneanother a row of stitches of one face and a row of stitches of the otherface, the two rows being racked in relation to one another in theknitting direction.
 12. Knitted fabric according to claims 9 to 11,characterized in that it has a minimum thickness of 3 mm.